Luigi Mangione pleaded not guilty Friday to federal charges in the fatal shooting of UnitedHealthcare CEO Brian Thompson in New York City last year.
Appearing inside federal court in Manhattan for his arraignment — Mangione wearing a brown prison jumpsuit — stood and entered his not guilty plea, according to reporters inside the courthouse.
The 26-year-old was indicted last week by a federal grand jury on four counts, including stalking and murder through the use of a firearm — the latter of which carries a maximum sentence of death.
The Justice Department filed a formal notice Thursday saying that it intends to seek the death penalty after Attorney General Pam Bondi directed the DOJ to seek the maximum punishment.
"Mangione's murder of Brian Thompson — an innocent man and father of two young children — was a premeditated, cold-blooded assassination that shocked America," Bondi said in a statement earlier this month. "After careful consideration, I have directed federal prosecutors to seek the death penalty in this case as we carry out President Trump's agenda to stop violent crime and Make America Safe Again."
In late December, Mangione was indicted on 11 state charges in New York, including murder and terrorism. He pleaded not guilty.
Mangione is also facing state charges in Pennsylvania, where he was arrested following a weeklong manhunt. The charges there include possession of an unlicensed firearm, forgery and providing false identification to police. He was extradited to New York before entering a plea.
He is being held without bond at the Metropolitan Detention Center Brooklyn, where Sean "Diddy" Combs and other high-profile defendants are also awaiting trial.
How authorities say the killing unfolded
Mangione is accused of fatally shooting Thompson on Dec. 4 outside the New York Hilton, where UnitedHealthcare's parent company, UnitedHealth Group, was holding its annual investor conference.
According to the Manhattan District Attorney’s Office, Mangione arrived in New York City by bus on Nov. 24 and checked into a hostel on the Upper West Side under the name "Mark Rosario," using a fake New Jersey ID.
On the morning of Dec. 4, investigators say, Mangione left the hostel around 5:30 a.m. ET and traveled to midtown near the Hilton hotel.
As Thompson was walking up to the hotel, Mangione took out a 9mm, 3D-printed ghost gun equipped with a 3D-printed suppressor and shot him once in the back and once in the leg.
Mangione fled the scene on a bicycle, setting off a five-day, nationwide manhunt.
He was arrested at a McDonald's in Altoona, Pa., on Dec. 9 with the same fake New Jersey identification and the 3D-printed ghost gun, as well as a handwritten document that police said appeared to be a “manifesto.”
Police said Mangione’s fingerprints matched those collected by the NYPD on a water bottle and a KIND bar wrapper recovered near the scene of the shooting and on a cellphone found in an alley near the hotel.
The search for a motive
Authorities have yet to officially identify a motive in Thompson’s slaying.
According to the federal complaint unsealed in December, the FBI said that writings in the handwritten notebook Mangione had with him when he was arrested showed his "hostility towards the health insurance industry and wealthy executives in particular." In one entry, Mangione wrote that "the target is insurance," according to the FBI.
NYPD Chief of Detectives Joseph Kenny previously told reporters that there did not appear to be "any specific threats" mentioned in the manifesto, but "it does seem that he has some ill will toward corporate America.”
Mangione was not a customer of UnitedHealthcare, but police said he had identified the company as one of the largest corporations in America in the document.
“So that’s possibly why he targeted that company,” Kenny later said in an interview with NBC New York.
Police also reportedly recovered shell casings at the scene with the words "deny," "defend" and "depose" written on them — echoing the title of a 2010 book, "Delay, Deny, Defend," that was highly critical of the insurance industry and describes how insurers avoid paying claims.
According to the federal complaint unsealed, the FBI said that writings in the handwritten notebook Mangione had with him when he was arrested showed his "hostility towards the health insurance industry and wealthy executives in particular."
‘Free Luigi’ movement
The killing sparked a national conversation about the U.S. health care system — with people sharing stories about denied insurance claims — and made Mangione a hero in the eyes of some who share his apparent outrage over corporate greed.
At a procedural court hearing in lower Manhattan in February, dozens of people wearing "Free Luigi" shirts and carrying homemade signs braved frigid temperatures for hours to show their support for Mangione.
“I don’t condone murder, but what he did and its focus on UnitedHealthcare has really brought to life how our health care system is broken,” Shane Solger, one of the demonstrators outside the hearing, told Yahoo News. “I’m here because the way that our health care system is designed right now hurts people. This is kind of a protest of our health care system.”
Mangione's supporters again gathered outside the courthouse on Friday. They were met by at least one counterprotester, New York artist Scott LoBaido, who brought with him a sculpture of Mangione in an electric chair.
Who is Luigi Mangione?
Mangione was born on May 6, 1998 in Towson, Md., and raised by a prominent Maryland family. His grandfather was a real estate developer who owned country clubs in Maryland. And he is the cousin of Maryland Republican State Delegate Nino Mangione.
He graduated in 2016 as a valedictorian from Gilman School, a private all-boys school in Baltimore. Mangione then attended the University of Pennsylvania, where he graduated in 2020 with a dual bachelor's degree in computer engineering and a master’s degree in computer and information science.
Mangione's last known address was in Honolulu.
Some of the people who knew him in Hawaii said he told them he had been suffering from back pain following spinal surgery.
According to friends and family, Mangione stopped communicating with them about six months before Thompson’s killing.
Who was Brian Thompson?
Thompson worked for UnitedHealthcare, the nation’s largest private health insurer, for 20 years.
Thompson was named CEO in April 2021, after having previously served as the CEO of UnitedHealthcare's government programs, including Medicare & Retirement, according to his company profile. He joined the company in 2004.
Before that, Thompson was a practicing CPA at PricewaterhouseCoopers LLP, serving as a manager in the transaction advisory services group of the company’s audit practice, according to his LinkedIn profile.
Thompson earned a bachelor’s degree in Business Administration and Accounting from the University of Iowa. He graduated in 1997.
He was a husband and father of two children.
Thompson lived in Maple Grove, Minn., a suburb of Minneapolis.
His wife, Paulette Thompson, told NBC News that her husband told her he had been receiving threats.
"There had been some threats," she said. "I don’t know details. I just know that he said there were some people that had been threatening him."